Add warframe CDN details

cache_domains.json

@@ -100,6 +100,11 @@
 			"description": "CDN for twitch games / mods and addons",
 			"domain_files": ["twitch.txt"]
 		},
+		{
+			"name": "warframe",
+			"description": "CDN for Warframe",
+			"domain_files": ["warframe.txt"]
+		},
 		{
 			"name": "wargaming",
 			"description": "CDN for wargaming.net",

warframe.txt

@@ -0,0 +1 @@
+content.warframe.com